Vibration regulator for dynamos



July 16, 1935. J. BoHu 29008s057 VIBRATION REGULATOR FOR DYNAMOS Filed March 30, 1933 Fig. 1 Fi 2 Jm en for-.-

Patented July 16, 1935 UNITED STATES PATENT OFFICE Application March 30, 1933, Serial No. 663,545 In Germany March 31, 1932 2 Claims.

The invention relates to regulating devices comprising resistances which are switched in steps; these resistances are alternately shortcircuited for regulating purposes of the machine by contacts fixed to separate springs, and switched into the exciting circuit when the contacts are opened. In known devices of this kind the movable contacts are arranged on a resilient member which is fixed to the armature of the regulator. Such arrangements have the disadvantages that the opening is made by an interposed resilient member i. e. not by a positive connection. If the contact surfaces do not wear off equally, the contact of the pairs of contacts is no longer reliable and in consequence of this the regulation becomes irregular, i. e. unsteady, but takes place under high drops of voltage.

This disadvantage is overcome according to this invention in such a way that the contacts are positively opened one after the other in the order in which they are disposed beside one another, by means of a non-elastic armature plate.

On the drawing a constructional form of the invention is shown.

Fig. 1 is a front view of the regulating device.

Fig. 2 is a plan view.

Fig. 3 is a diagrammatical view of the invention.

In the figures A represents the regulating coil, B the core of the same. C is the armature which acts against the force of the spring I. The contact springs D are riveted to the underside of the armature C at the point F. At the end of said springs D the contacts proper E are disposed. Opposite to the latter the countercon-tacts G are mounted into a rigid frame. The contacts E extend right through the openings H of the armature plate C. After all contacts have been closed, the resistances Wl to W4 are shortcircuited by the plate C (see Figure 3). When the armature plate C is attracted by the electromagnet AB, first the contact El which is the shortest one, is positively opened by the armature plate and thereby the resistance W switched into the exciting circuit of the machine. The regulation first takes place by switching in and out this resistance WI. As soon as the number of revolutions increases the resistances W2, W3, W4 are switched in after one another by opening the contacts E2, E3, E4. When the armature returns to its original position, in consequence of the decrease of the speed, the resistances are shortcircuited again after one another.

In order to obtain the smallest voltage drops from one step of regulation to the next one, the contact springs D must have a certain initial tension; the difference of these initial tensions from one contact spring to the next one must correspond to the increase in the strength of field which acts on to the armature plate when the latter is approaching the magnet coil from one step of regulation to the next one. If the initial tension of the contact springs would be higher than these values, a greater increase of tension would be necessary to attain the next step of regulation.

The new feature of this regulation consists in that it is a positive one from one resistance to the next one and that the tension of the contact springs is regulated in a distinct way whereby a quick regulation into the new condition is obtained without great drop of voltage.

What I claim is:

1. In regulating devices, in combination a regulating coil, a regulating spring, a coil core, a stationary armature, a rigid armature plate movably fixed to the latter and spring-biased away from the coil, resistances, terminals for the latter, stationary contacts connected to said terminals for said resistances, movable contacts, the latter forming together with said stationary contacts pairs of regulating contacts, separate springs for each of said movable contacts, the latter being mounted on the armature to move therewith, said movable contacts being of successively and uniformly increased length and extending through apertures of said rigid armature plate, said springs having successively increased initial tensions, said pairs of contacts being adapted to be positively opened after one another in the order in which they are disposed beside one another thereby switching said resistances in and out.

2. In regulating devices, in combination a regulating coil, a regulating spring, a coil core, a stationary armature, a rigid armature plate movably fixed to the latter and spring biased away from the coil, resistances, terminals for the latter, stationary contacts connected to said terminals for said resistances, movable contacts, the latter forming together with said stationary contacts pairs of regulating contacts, separate springs for each of said movable contacts, said springs being mounted on the armature to move herewith, said movable contacts being of successively and uniformly increased length and extending through apertures of said rigid armature plate, said springs having successively increased initial tensions, said pairs of contacts being adapted to be positively opened after one another in the order in which they are disposed beside one another thereby switching said resistances in and out.

JAKOB BOHLI. 

